Time to patch (Intel released new firmware) and go on with life. Keys in secure hardware reportedly can be exposed in as little as a few minutes:

…timing leakage on Intel firmware-based TPM (fTPM) as well as in STMicroelectronics’ TPM chip. Both exhibit secret-dependent execution times during cryptographic signature generation. While the key should remain safely inside the TPM hardware, we show how this information allows an attacker to recover 256-bit private keys…